2025 Ronstan Marine Catalogue - Catalog - Page 63
KEELBOAT BLOCKS
Series 100 CORE
61
RF104100
RF104200
RF104110
RF104151
2 x 12mm (7/16”)
RF104108A
RF104140
22mm
(7/8”)
RF104108A suits 22mm (7/8”)
mast collar post (not supplied)
4 x 8mm (5/16”)*²
22mm (7/8”)
Universal head can be fixed at 0° or 90° or
left free to swivel, by using a 2.5mm hex key.
Mainsheet, spinnaker sheet, vang, halyard and
backstay applications on boats to 16m (53ft).
Bearings: High compression strength,
self-lubricating acetal.
RF104108A halyard block has removable
12mm (1/2”) clevis pin to suit a 22mm (7/8”)
wide mast collar post.
General applications on larger yachts.
Head post: Grade 2205 stainless steel.
Cheek plates: Aluminium alloy.
Shackles: Grade 17-4PH stainless steel.
Sheaves: Glass fibre reinforced nylon.
Padeye: Grade 15-5PH stainless steel.
Other fixtures: Grade 316 stainless steel.
PRODUCT No.
DESCRIPTION
Ball Bearing
RF104100
Single block, universal head
RF104108A
Halyard block, clevis pin head
RF104110
Single block, becket, universal head
RF104140
Stand-up block, swivelling
RF104151
Foot block, single
RF104200
Double block, universal head
SHEAVE
DIAM.
mm
MAX.
ROPE
mm
PIN
DIAM.
mm
100
100
100
100
100
100
18
18
18
18
18
18
10
12
10
10
M.W.L.
kg
B.L.
kg
3250
7500
3250*1 7500*1
3250
7500
3000 6000*2
3250
7500
3250
7500
WEIGHT
g
SHEAVE
DIAM.
in
MAX.
ROPE
in
900
614
1098
1138
700
1400
4
4
4
4
4
4
3/4
3/4
3/4
3/4
3/4
3/4
*1 Full block rated load can only be achieved with uniformly distributed load across full length of clevis pin. i.e. 22mm (7/8”) diameter mast collar post or 22mm (7/8”) wide mast collar plate/tang.
*2 A4-80 DIN7991 grade fasteners recommended to achieve BL
PIN
DIAM. M.W.L.
in
lb
3/8
1/2
3/8
3/8
7150
7150*1
7150
6600
7150
7150
B.L.
lb
WEIGHT
oz
16500
16500*1
16500
13200*2
16500
16500
31.8
21.7
38.8
40.2
24.7
49.5
